Sharpening device for a writing element

ABSTRACT

A device for sharpening a writing element mounted in a holder when the writing element is inserted into an eccentric opening in the device and moved in a circular path to rotate a sharpening tool round the element. The opening is formed in a rotary part of a casing and the sharpening tool is carried in a toolholder mounted adjacent said opening, as in a ball-and-socket joint, so that the toolholder may tilt during sharpening and so minimize the danger of breakage of said writing element but the toolholder is held against rotation with the writing element.

United States Patent Inventor Peter Dziuk Nurnberg, Germany Appl. No. 781,112 Filed Dec. 4, I968 Patented Feb. 9, 1971 Assignee U.S. Staedtler Numberg, Germany a firm Priority Dec. 7, 1967 Germany St 22 015 SHARPENING DEVICE FOR A WRITING ELEMENT 7 Claims, 4 Drawing Figs.

US. Cl l44/28.4 Int. Cl 843i 23/00 Field of Search l44/28.4,

[5 6] References Cited UNITED STATES PATENTS 1,878,617 9/1932 Bair 144/284 Primary Examiner-Theron E. Condon Assistant Examiner-Roscoe V. Parker, J r. Attorney-Hane & Baxley ,Il/illllllli 4 PATENTEDFEB slsm 3561-507 FIG. 2

uvmvron. P: "r: a v U z z 14 K v/WW 4 ATTORNEYS SI'IAIIPENING DEVICE lFOR A WRITING ELEMENT BACKGROUND OF THE INVENTION This invention relates to a device for sharpening a writing element mounted in a holder, wherein the point of the writing element is insertable into an opening in a rotatable part of a casing of the device and rotated in relation to a sharpening tool in the casing whilst being maintained in contact therewith.

In a known pencil sharpener of this kind, the casing is potshaped and a milling or abrading tool is arranged at the center of the casing, and the point of the lead is rotated about the tool after having been inserted into an opening in the casing. However, the pencil lead is relatively rigidly guided and is, therefore, liable to break. Furthermore, contact with the sharpening tool is rather irregular. In order to eliminate these shortcomings, another proposed sharpener contains a sharpening tool which is mounted in the casing by means of a universal joint; however, this makes the contrivance expensive and, moreover, the universal joint cannot be encased to make it dustproof.

It is an object of the present invention to overcome the disadvantages indicated above, in a manner that is structurally simple and practicable for everyday use.

SUMMARY OF THE INVENTION According to the present invention there is provided a device for sharpening a writing element mounted in a holder, the device comprising a casing including a rotatable part provided with an eccentric socket; sharpening means for sharpening said writing element when rotated relatively thereto; a ball-like member mounted in said socket and carrying said sharpening means; and resilient meansadapted to resiliently oppose tilting movement of said ball-like member in said socket and to effectively prevent rotation of said ball-like member in said socket, when said writing element is inserted into said sharpening means and said rotatable part is rotated by generally circular movement of said writing element mounted in its holder.

Suitably, said ball-like member constitutes a toolholder for a sharpening tool.

In a simple form of construction, the sharpening tool is an ordinary knife blade. However, within the scope of the invention, several such blades or a milling or abrading tool may be provided. The toolholder and the sharpening tool are moved around the pivot of the rotatable part of the casing by the user grasping the holder of the writing element and guiding it around this pivot in a roughly circular path. The disposition of the toolholder in a bearing similar to a ball-and-socket joint permits the angularity of the holder and of the writing element to vary, since it permits the toolholder to participate in any tilting deflection. During rotation about. the pivot of the rotatable part of the casing, which is usually a rotatable cover of a circular box, the cutting tool will rotate about the point of the writing element, and the writing element will therefore be for the reception of the ball-like toolholder is formed by an opening in the rotatable part of the casing and a bearing member which is fixed to said part. The bearing member is provided with means arranged to prevent the toolholder from rotating together with the writing element.

The toolholder projects through the opening in the casing which forms part of the bearing and is held in the opening by the bearing member which is fixed to the inside of the casing and which likewise has a spherical bearing surface. Although the toolholder is universally deflectable in this socket-shaped bearing, it is restrained from rotating about its axis. Generally, it will be sufficient to restrict possible rotation of the toolholder to within narrow angular limits, so that the required relative motion between the sharpening tool and the writing element will take place when the part of the casing containing the toolholder rotates.

According to yet another feature of the invention, the bearing member may carry a frame which embraces the tool holder, like a bail, on the side remote from that containing the opening for the insertion thereinto of the writing element, and at least one resilient element may be provided for urging the toolholder to remain its central position and preventing it from rotating together with the writing element. The bearing member may alternatively have the fiormof a basket-shaped member with the same useful effect.

The resilient element may consist of one or more coiled compression springs or rubber or like members. According to the invention the resilient element is arranged to be laterally deflectably but nonrotatably attached to the toolholder and to the baillike frame so that the toolholder is deflectable in its socket but not rotatable about an axis coinciding with that of the inserted writing element. If a compression spring is used, which is attached both to the toolholderand to the bail, then this spring can yield to some extent to rotation of the toolholder. However, the simultaneous increase in the resistance of the coil will prevent any such rotation of the toolholder from continuing.

Other features, details and advantages of theinvention will be understood from the following description of preferred embodirnents of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS I FIG. I is a plan view of a sharpening device; FIG. 2 is a section on the line II-II of FIG. I; FIG. 3 is a detail section on the line llII-III of FIG. 1; and, FIG. 4 shows a modifiedconstruction of the detail shown in FIG. 3.

' DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 3 of the drawings, the device comprises a container 1 and a cover 2 having on its underside a central bushing 3 which is rotatable on a pin 6 screwed into a socket 4 formed on the inside of the container bottom 5. The container 1 serves for the reception of dust or cuttings produced during sharpening. Furthermore, the cover is formed with an eccentric opening 7having a part-spherical shape. An annular bearing member 9 is secured by screws to underside 8 of the cover 2 in alignment with the opening 7,

and the internal surface of this bearing member continues the spherical shape of 'the opening 7. The plane separating the bearing member 9 and the cover 7 roughly defines the equatorial plane of a sphere. The bearing member 9 carries a frame l 10 in the form of a bail which projects into the interior of the container. I

The bearing member 9 and the opening 7 in the cover 2 together form a part-spherical socket for a toolholder II which has the form of a ball and carries a boss 12. The boss 12 likewise projects into the container interior for attachment thereto of one end of a coiled compression spring 13 of which the other end is anchored, so that it cannot rotate, on a pin 14 screwed into the frame 10. Thus, if the ball-like toolholder ll i is angularly deflected out of its position shown in FIGS. 2 and 3, the compression spring 13 will operate to return it at least approximately into its former position. Since the compression spring 13 is firmly attached both to the pin 14 and to the boss 12, the toolholder 11 cannot rotate in its socket, or only a very restricted degree of rotation is possible.

The outwardly projecting part of the toolholder 11 contains an opening 15 for the insertion thereinto of the end of the writing element to be sharpened. The interior of the toolholder 1 1 contains the sharpening tool. which, in the illustrated Y embodiment, is a replaceable knife blade 16.

If the end of a writing element to be sharpened is inserted into the opening 15 of the toolholder l1, and the holder in which the writing element is mounted is used to rotate the cover 2 of the container 1 about its pivot pin 6, in the direction indicated by the arrow 17, the point of the writing element will rotate against the edge of the sharpening tool 16 and the writing element will be sharpened. The dust produced collects inside the container l.

In the embodiment illustrated in FIG. 4, the boss 12, which is formed on the toolholder 11 and which projects into the frame H0, is positioned on each side by a coil spring 18, both coil springs being adjustably held in the frame by screws 19.

Instead of having a bail-shaped form, the frame 10 may be basket-shaped. Moreover, if desired, an additional pair of springs 18 may be disposed in such a basket at right angles to the pair of springs shown in FIG. 4, to provide further positioning for the boss E2 on the toolholder 11.

Further modifications to the above description may also be made without departing from the scope of the following claims.

lclaim:

l. A device for sharpening a writing element mounted in a holder, the device comprising a casing including a rotatable part provided with an eccentric socket; sharpening means for sharpening said writing element when rotated relatively thereto; a ball-like member mounted in said socket and carrying said sharpening means; and resilient means adapted to resiliently oppose tilting movement of said ball-like member in said socket and to effectively prevent rotation of said ball-like member in said socket, when said writing element is inserted into said sharpening means and said rotatable part is rotated by generally circular movement of said writing element mounted in its holder.

2. A device as claimed in claim 1, in which a bearing member is secured to said rotatable part of said casing and said socket is formed by an opening in said rotatable part and an opening in said bearing member, which openings have partspherical bearing faces.

3. A device as claimed in claim 1, in which an inner frame member is secured to said rotary part adjacent said socket to embrace part of said ball-like member within said casing, and said resilient means comprise at least one resilient member extending between said frame member and said ball-like member.

4. A device as claimed in claim 3, in which said resilient member comprises an axial spring adapted to permit deflection but to resist rotation.

5. A device'as claimed in claim 3, in which said resilient means comprise a pair of opposed transverse springs.

6. A device as claimed in claim 1, in which said sharpening means comprise a blade which is mounted in said ball-like member.

7. A device as claimed in claim 1, in which said sharpening means said ball-like mmber comprise a single integral part. 

1. A device for sharpening a writing element mounted in a holder, the device comprising a casing including a rotatable part provided with an eccentric socket; sharpening means for sharpening said writing element when rotated relatively thereto; a ball-like member mounted in said socket and carrying said sharpening means; and resilient means adapted to resiliently oppose tilting movement of said ball-like member in said socket and to effectively prevent rotation of said ball-like member in said socket, when said writing element is inserted into said sharpening means and said rotatable part is rotated by generally circular movement of said writing element mounted in its holder.
 2. A device as claimed in claim 1, in which a bearing member is secured to said rotatable part of said casing and said socket is formed by an opening in said rotatable part and an opening in said bearing member, which openings have part-spherical bearing faces.
 3. A device as claimed in claim 1, in which an inner frame member is secured to said rotary part adjacent said socket to embrace part of said ball-like member within said casing, and said resilient means comprise at least one resilient member extending between said frame member and said ball-like member.
 4. A device as claimed in claim 3, in which said resilient member comprises an axial spring adapted to permit deflection but to resist rotation.
 5. A device as claimed in claim 3, in which said resilient means comprise a pair of opposed transverse springs.
 6. A device as claimed in claim 1, in which said sharpening means comprise a blade which is mounted in said ball-like member.
 7. A device as claimed in claim 1, in which said sharpening means said ball-like member comprise a single integral part. 